1. Field of the Invention
This invention relates to a wheel cylinder adjuster, particularly to one able to adjust the left-sided and the right-sided wheel cylinders of an automobile by means of a single driving wrench cooperating with an actuating disc.
2. Description of the Prior Art
A conventional wheel cylinder adjuster, as disclosed in a Taiwanese patent No. 392552, titled “Improved pump adjustment device structure of a disc brake” includes an actuating disc able to be axially jointed with a wheel cylinder, and a driving wrench able to be jointed with the actuating disc and actuated to rotate and shift axially. The actuating disc is provided with a hollow cylindrical positioning shaft protruding upward at a dead center of the disc surface, and the positioning shaft has its outer diameter corresponding with the inner diameter of the central valve port of the wheel cylinder. Two pivotal holes are respectively bored at locations of two ends of the diameter of the positioning shaft, and at least one positioning hole is bored at a reserved end of a radius of the outer circumference of the positioning shaft for a positioning post to be axially fixed therein. The driving wrench has an axial end mounted with a driving disc having its center formed with a receiving recess secured therein with a powerful magnet, and the receiving recess has its outer circumference disposed with two fixing studs protruding upward at locations respectively corresponding with the pivotal holes of the actuating disc so that the actuating disc can quickly be attracted by the powerful magnet and firmly combined with the driving wrench. By so designing, the wheel cylinder can quickly be disassembled with great convenience and with stability by having the positioning shaft of the actuating disc aligned to and fitted in the central valve port of the wheel cylinder and having the reserved positioning post resisting against a notch at one side of the wheel cylinder.
However, the conventional wheel cylinder adjuster must prepare two different driving wrenches 10 and 11 in a tool box 1, referring to FIG. 1. The threaded rod 100 of the driving wrench 10 is provided with right-handed threads while the threaded rod 110 of the driving wrench 11 is formed with left-handed threads for respectively adjusting the right-sided and the left-sided wheel cylinders of an automobile, thus elevating cost in manufacturing and purchasing an additional driving wrench and rendering increase of the whole weight of a tool box.